docs: def get_hints(self, plugin):
          ''' Return plugin hints from ``plugin``. '''
          hints = []
  
          for hint_name in getattr(plugin, 'hints', []):
              hint_plugin = self._plugins.get(hint_name)
              if hint_plugin:
                  hint_result = Result(
                      name=hint_plugin.name,
                      homepage=hint_plugin.homepage,
                      from_url=self.requested_url,
                      type=HINT_TYPE,
                      plugin=plugin.name,
                  )
                  hints.append(hint_result)
  
                  logger.debug(f'{plugin.name} & hint {hint_result.name} detected')
              else:
                  logger.error(f'{plugin.name} hints an invalid plugin: {hint_name}')
  
          return hints